From: Joe Perches <joe@perches.com>
To: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: iommu@lists.linux-foundation.org,
LKML <linux-kernel@vger.kernel.org>,
Joerg Roedel <joro@8bytes.org>,
Lu Baolu <baolu.lu@linux.intel.com>,
David Woodhouse <dwmw2@infradead.org>,
"Tian, Kevin" <kevin.tian@intel.com>,
Raj Ashok <ashok.raj@intel.com>, Yi Liu <yi.l.liu@intel.com>,
Eric Auger <eric.auger@redhat.com>,
"Mehta, Sohil" <sohil.mehta@intel.com>
Subject: Re: [PATCH v4 8/8] iommu/vt-d: Misc macro clean up for SVM
Date: Mon, 02 Dec 2019 10:22:13 -0800 [thread overview]
Message-ID: <3de5bad2f414fb36d1f54dd610ffeecb2c989143.camel@perches.com> (raw)
In-Reply-To: <20191202101553.079898a3@jacob-builder>
On Mon, 2019-12-02 at 10:15 -0800, Jacob Pan wrote:
> On Thu, 21 Nov 2019 13:37:10 -0800
> Joe Perches <joe@perches.com> wrote:
>
> > On Thu, 2019-11-21 at 13:26 -0800, Jacob Pan wrote:
> > > Use combined macros for_each_svm_dev() to simplify SVM device
> > > iteration and error checking.
> > []
> > > diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
> > []
> > > +#define for_each_svm_dev(sdev, svm, d) \
> > > + list_for_each_entry((sdev), &(svm)->devs, list) \
> > > + if ((d) != (sdev)->dev) {} else
> > > +
> > > int intel_svm_bind_mm(struct device *dev, int *pasid, int flags,
> > > struct svm_dev_ops *ops) {
> > > struct intel_iommu *iommu = intel_svm_device_to_iommu(dev);
> > > @@ -274,15 +278,13 @@ int intel_svm_bind_mm(struct device *dev, int
> > > *pasid, int flags, struct svm_dev_ goto out;
> > > }
> > >
> > > - list_for_each_entry(sdev, &svm->devs,
> > > list) {
> > > - if (dev == sdev->dev) {
> > > - if (sdev->ops != ops) {
> > > - ret = -EBUSY;
> > > - goto out;
> > > - }
> > > - sdev->users++;
> > > - goto success;
> > > + for_each_svm_dev(sdev, svm, dev) {
> > > + if (sdev->ops != ops) {
> > > + ret = -EBUSY;
> > > + goto out;
> > > }
> > > + sdev->users++;
> > > + goto success;
> > > }
> >
> > I think this does not read better as this is now a
> > for_each loop that exits the loop on the first match.
> >
> I think one of the benefits is reduced indentation. What do you
> recommend?
Making the code intelligible for a reader.
At least add a comment describing why there is only
a single possible match.
Given the for_each name, it's odd code that only the
first match has an action.
next prev parent reply other threads:[~2019-12-02 18:22 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-21 21:26 [PATCH v4 0/8] VT-d Native Shared virtual memory cleanup and fixes Jacob Pan
2019-11-21 21:26 ` [PATCH v4 1/8] iommu/vt-d: Fix CPU and IOMMU SVM feature matching checks Jacob Pan
2019-11-21 21:26 ` [PATCH v4 2/8] iommu/vt-d: Match CPU and IOMMU paging mode Jacob Pan
2019-11-21 21:26 ` [PATCH v4 3/8] iommu/vt-d: Reject SVM bind for failed capability check Jacob Pan
2019-11-21 21:26 ` [PATCH v4 4/8] iommu/vt-d: Avoid duplicated code for PASID setup Jacob Pan
2019-11-21 21:26 ` [PATCH v4 5/8] iommu/vt-d: Fix off-by-one in PASID allocation Jacob Pan
2019-11-21 21:26 ` [PATCH v4 6/8] iommu/vt-d: Replace Intel specific PASID allocator with IOASID Jacob Pan
2019-11-21 21:26 ` [PATCH v4 7/8] iommu/vt-d: Avoid sending invalid page response Jacob Pan
2019-11-21 21:26 ` [PATCH v4 8/8] iommu/vt-d: Misc macro clean up for SVM Jacob Pan
2019-11-21 21:37 ` Joe Perches
2019-12-02 18:15 ` Jacob Pan
2019-12-02 18:22 ` Joe Perches [this message]
2019-12-02 19:51 ` Jacob Pan
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=3de5bad2f414fb36d1f54dd610ffeecb2c989143.camel@perches.com \
--to=joe@perches.com \
--cc=ashok.raj@intel.com \
--cc=baolu.lu@linux.intel.com \
--cc=dwmw2@infradead.org \
--cc=eric.auger@redhat.com \
--cc=iommu@lists.linux-foundation.org \
--cc=jacob.jun.pan@linux.intel.com \
--cc=joro@8bytes.org \
--cc=kevin.tian@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=sohil.mehta@intel.com \
--cc=yi.l.liu@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).